Stern Whitestar Driver I/O Help!!!

[Courtney Blush]

Hey guys,

I am saying this is Driver but it could just as easily be CPU.

Basically I get no playfield life except GI. Inserts, Flashers and coils all dead.

We have DMD and sound and switches which are obviously CPU based and the blanking LED is solid.

I have replaced the 20 pin cable, checked the solenoids fire from their tabs shorted to ground, changed the 2 x 74LS138 decoders, changed all 5 caps, changed the 5v BR and have a stable 5.01v

What else can possibly cause this as there are not that many things that can affect everything.

Regards

Courtney

 

[Alpha1]

Anyone got any help for her guys?

 

[Courtney Blush]

Thanks for the bump Oliver, I forgot I had asked here. It's not sorted, every logic IC on the board was almost a dead short but not enough to blow the fuse, just ran the regulator really hot. Somone had obviously had a problem and ran the board on too high a voltage frying all the IC's in the process.

 

[Moonraker]

Check that all the tilt mechanisms in the game are connected and registering properly. Then check to see if the tilt relay is energised or not. You could try manually pushing the contact switch (with a stick. careful of the voltages that may be involved) to see if the game starts or not.

 

[Courtney Blush]

Hi,

I haven't got that far yet due to the driver board being toast. I don't envisage any issues once the IC's are replaced

C

 

[Alpha1]

Ouch that sucks on the power driver board, it was the only one I had. Glad to hear you're in the process of changing the ICs.

 

[ronnie63]

Acid spill on the cpu can cause all kinds of issues as can poor ribbons and header pins, I think the DMD boots on it's own as it has it's own cpu so that might lead you up the wrong path?

Cheers Ronnie

 

[Moonraker]

I have found that for a few Sega/Stern's you need a working MPU, driver board and display driver board before a game will boot.

 

[Courtney Blush]

The CPU and Display are booting fine. Just the badly damaged Driver. No Acid damage on this as the battery pack was removed a long time ago and NVRAM fitted

 

[ronnie63]

In that case maybe it's the small monitoring ic on the driver board it checks for voltage and data transfer from the cpu and vice versa. the cpu board also has one?

 

[Courtney Blush]

The watchdog IC was doing it's job fine. The 5v rail was being dragged down to 4.1 and also the logic level was 1.36. Hopefully the new logic IC's should arrive tomorrow.

Gave me a good excuse to deep clean the machine